The University Health Network has the busiest right lobe live liver donor program in North America with a stable rate of approximately 50 cases per year. We have performed a total of 282 right lobe liver donor operations with no permanent donor morbidity and no donor deaths. Our 5-year graft survival rates are >80% comparable to the results of deceased donor transplantation at our center We have been acadmically productive with 17 manuscripts on our live donor experience published or in press. Membership in the A2ALL consortium will build on our strong record of successful collaborative liver transplant studies. AIM 1: To contribute to the A2ALL prospective longitudinal studies of donor and recipient outcomes through participation in co-investigator studies; and the collection, contribution, and analysis of our data and biospecimens. AIM 2: To conduct and complete two site-initiated investigator studies: a) A comprehensive, longitudinal, cohort study of donor morbidity, mortality and health related quality of life (HRQOL) using donors that have been excluded on anatomic grounds as controls. b) A study to determine if plasma and liver tisssue expression of the novel CD4(+)CD25(+) regulatory T cell effector molecule - fibrinogen-like protein 2 (FGL2) - can be used as a biomarker for i) the rapidity and severity of hepatitis C recurrence after live donor liver transplantation; and ii) the response to treatment of recurrence after live donor liver transplantation. Live donor liver transplants provide an ideal model to test this hypothesis because there is limited outcome variation due to the variability in the health of the donor liver and organ preservation times are relatively constant.